Biomass burning (BB) is a significant air pollution source, with global, regional and local impacts on air quality, public health and climate. Worldwide an extensive range of studies has been conducted on almost all the aspects of BB, including its specific types, on quantification of emissions and on assessing its various impacts. China is one of the countries where the significance of BB has been recognized, and a lot of research efforts devoted to investigate it, however, so far no systematic reviews were conducted to synthesize the information which has been emerging. Therefore the aim of this work was to comprehensively review most of the studies published on this topic in China, including literature concerning field measurements, laboratory studies and the impacts of BB indoors and outdoors in China. In addition, this review provides insights into the role of wildfire and anthropogenic BB on air quality and health globally. Further, we attempted to provide a basis for formulation of policies and regulations by policy makers in China.

Humans can be infected by SARS-CoV-2 either through inhalation of airborne viral particles or by touching contaminated surfaces. Structural and functional studies have shown that a single RBD of the SARS-CoV-2 homotrimer spike glycoprotein interacts with ACE2, which serves as its receptor 1,2 . Binding of spike (S) protein to ACE2 and subsequent cleavage by the host protease transmembrane serine protease 2 (TMPRSS2) results in cell and virus membrane fusion and cell entry 1 . Blocking of the ACE2 receptor by specific antibodies prevents viral entry 1,3-5 . In vitro binding measurements have shown that SARS-CoV-2 S protein binds ACE2 with an affinity of around 10 nM, which is about tenfold tighter than the binding of the SARS-CoV S protein 2,4,6 . It has been suggested that this is, at least partially, responsible for the higher infectivity of SARS-CoV-2 7 . Recently, three major SARS-CoV2 variants of concern have emerged and mutations in the RBD of the spike proteins of these variants have further strengthened this hypothesis. Deep-mutational scanning of the RBD domain showed that the N501Y mutation in the Alpha variant to enhances binding to ACE2 7 . The Beta variant has three altered residues in the ACE2-binding site (K417N, E484K and N501Y), and has spread extremely rapidly, becoming the dominant lineage in the Eastern Cape and Western Cape Provinces within weeks 8 . The Gamma variant, with independent K417T, E484K and N501Y mutations, similar to the B.1.351 variant is spreading rapidly from the Amazon region 9 . Another S mutation associated with increased SARS-CoV-2 infectivity is S477N, which became dominant in many regions 10 .Efficacious vaccines are now being administered 11 . However, especially when a large fraction of the global population remains unvaccinated, the potential of the continuously mutating virus to become at least partially resistant to vaccines means that drug development must continue. Potential therapeutic targets that block viral entry include molecules that block the spike protein, the TMPRSS2 protease or the ACE2 receptor 12 . Multiple high-affinity neutralizing antibodies have been developed 13 . Soluble forms of the ACE2 protein 14,15 or engineered parts or mimics have also shown efficacy 16,17 . In addition, previously developed TMPRSS2 inhibitors have been repurposed for treatment of COVID-19 1 .The development of molecules to block the ACE2 protein has not received much attention. One potential caveat with this approach is the importance of ACE2 biological activity, both as a carboxypeptidase removing a single C-terminal amino acid from angiotensin II to generate angiotensin-(1-7) and in the regulation of amino acid transport and pancreatic insulin secretion 18,19 . Dalbavancin is a drug that blocks the spike protein-ACE2 interaction, however it does so with low affinity 20 (approximately 130 nM).We hypothesized that the RBD domain of SARS-CoV-2 could be used as a competitive inhibitor of the ACE2 receptor binding site. However, this would probably require an RBD with picomola...

Atmospheric brown carbon (BrC) is an important contributor to the radiative forcing of climate by organic aerosols. Because of the molecular diversity of BrC compounds and their dynamic transformations, it is challenging to predictively understand BrC optical properties. OH radical and O3 reactions, together with photolysis, lead to diminished light absorption and lower warming effects of biomass burning BrC. The effects of night-time aging on the optical properties of BrC aerosols are less known. To address this knowledge gap, night-time NO3 radical chemistry with tar aerosols from wood pyrolysis was investigated in a flow reactor. This study shows that the optical properties of BrC change because of transformations driven by reactions with the NO3 radical that form new absorbing species and lead to significant absorption enhancement over the ultraviolet–visible (UV-vis) range. The overnight aging increases the mass absorption coefficients of the BrC by a factor of 1.3–3.2 between 380 nm and 650 nm. Nitrated organic compounds, particularly nitroaromatics, were identified as the main products that contribute to the enhanced light absorption in the secondary BrC. Night-time aging of BrC aerosols represents an important source of secondary BrC and can have a pronounced effect on atmospheric chemistry and air pollution.

We use a new panel data set of credit card accounts to analyze how consumers responded to the 2001 federal income tax rebates. We estimate the monthly response of credit card payments, spending, and debt, exploiting the unique, randomized timing of the rebate disbursement. We find that, on average, consumers initially saved some of the rebate by increasing their credit card payments and thereby paying down debt. But soon afterward their spending increased, counter to the canonical permanent-income model. Spending rose most for consumers who were initially most likely to be liquidity constrained, whereas debt declined most (so saving rose most) for unconstrained consumers. More generally, the results suggest that there can be important dynamics in consumers' response to "lumpy" increases in income like tax rebates, working in part through balance-sheet (liquidity) mechanisms.

Polycomb group genes play crucial roles in the maintenance of the transcriptionally silenced state of genes for proper cell differentiation in animals and plants. While components of the polycomb repressive complex2 (PRC2) are evolutionarily conserved and their functions are extensively studied in plants, PRC1 differs considerably between animals and plants, and its functions in plants are as yet not well described. Previous studies have identified the Arabidopsis AtRING1a and AtRING1b as homologues of the animal PRC1 subunit RING1. Here, we show that the Atring1a Atring1b double mutant exhibits derepression of embryonic traits during vegetative growth. Accordingly, several key regulatory genes involved in embryogenesis and stem cell activity are ectopically expressed in the mutant. Furthermore, we show that the mutant phenotypes and increased expression of regulatory genes are enhanced by the PRC2 mutant clf. Finally, we show that three homologues of the animal PRC1-subunit ring-finger protein BMI1, AtBMI1a, AtBMI1b and AtBMI1c, can bind with AtRING1a or AtRING1b, and in addition, AtBMI1c can bind with LHP1. The Atbmi1a Atbmi1b double mutant shows derepression of embryonic traits similar to that of the Atring1a Atring1b double mutant. Interestingly, expression levels of AtBMI1a, AtBMI1b and AtBMI1c are elevated in the Atring1a Atring1b mutant and those of AtBMI1c, AtRING1a and AtRING1b are elevated in the Atbmi1a Atbmi1b mutant, suggesting a self-regulatory feedback mechanism. Taken together, our results illuminate crucial functions of the PRC1-like ring-finger components in stable repression of embryonic traits and regulatory genes for proper somatic growth.